import java.util.HashSet;

class Solution {
    public int numJewelsInStones(String jewels, String stones) {
        HashSet<Character> set = new HashSet<>();
        for (int i = 0; i <jewels.length() ; i++) {
            set.add(jewels.charAt(i));
        }
        int count=0;
        for (int i = 0; i <stones.length() ; i++) {
            if(set.contains(stones.charAt(i))){
                count++;
            }
        }
return count;
    }
}